I was out of town for a week and my husband took great care of our pool. I cleaned the skimmer basket late Thursday night and all was great. I then checked on it again early Saturday morning and cleared leaves out of the basket. When I turned the pump back on I noticed a leak on one side of the filter where the top and bottom are joined and the band seals them together. I'm thinking I need to open it and reseal the gasket. That'd be okay. But, when I turned on the pump, the sand filter "puffs up" ever so slightly. Puffs up as in expands a little bit. Naturally, it frightened me. I disconnected the pump and sand filter. I have set up the intex pump and cartridge filter that came with my pool for now until I can figure out what was going on with my sand filter. The water flow seemed to be fine and I have found no blockages any where from skimmer thru to the return. I did forget to open the intake and return when I turned the pump on about two weeks ago . It was only for a moment and I turned everything off, opened the intake and return, turned the pump back on and everything was fine. Then about a week later was when I noticed the filter puffing up and leaking. Anyone have any ideas? Is my filter dead?